Hello, Will here, i am new to the list. I have a 91 951 here in Germany and have some questions about the transaxle. Is it common to have noise in the unit when the clutch pedal is released in neutral? When I push the clutch pedal in neutral it goes away after a few seconds, but if i am rolling to a stop in say first, it does not go away until i have stopped.
Is this a common occurance? I am running royal Purple synthetic 75W90 in it and it helped the problem when it was very cold 30 degrees F, but as of late it is getting worse, and warmer.
I routinely run the car at 160+ mph on the autobahns, and I am not sure if the lubricant is up to it. Does any one have any good suggestions for Lubricants?

Thanks, Will

Oh and check out the Licence plate!

 

It is common to have noise when you idle in neutral especially when the gearbox is warmed up. The noise should not be that loud that you hear it when you costing to a halt in first gear. The 951 gearbox should have an oil cooler so it should handle the high speed. Not sure how well can it handle sustained high speed driving at that age but you should look for other types of noises in the gearbox. Some use heavier grade oil in high millage gearbox and report that the box gets quieter. Also I suspect you have limited slip diff which may require different lubricant worth double checking.

 

944 transmissions are noisy. Try to compare with other cars.
After few laps at track transmission makes really loud noise.

 

I am not sure about running thicker gear oil in it as it did get louder when it was colder. This might signify that a lighter weight oil would be better. It does have a LSD in it.

BTW, I went to the nurburgring the other day to see if i could do a lap or few, but would you believe it.....it was closed as they had a 24 hour race over the weekend and they needed to clean up the track. Next time, as it is only an hour and a half away.

Any more info on the transaxle would be most beneficial.

Thanks. Will

 

It sounds like torque tube bearings. If the transmission is in neutral and you engage the clutch by letting your foot off, it will make a clacking sound if your pilot bearing or torque tube bearings are out. Pilot bearings are known to destroy torque tube center shafts.

 

Search "fifth gear rattle". I have what you describe occasionally. I believe mine to be the fifth gear rattle and apparently it causes no harm.

I switched from the PO's Swepco (green stuff) to RedLine 75W90 and no discernible change.

 

No clunks when I do what you said.

 

Read from here http://www.clarks-garage.com/shop-ma...ure-index3.htm about trorque tube and other things.

 

Reading the first post, the first thing that jumped into my head was the pilot bearing like Lego said.

 

Mine was very noisy also. I tried several different transaxle oils prior to settling with Mobil 1 synthetic 75-90. I have noticed it is seeping a little around the seals and I plan on using RED LINE 75-90 next time I change it.

Mine has gone from "really" noisy, grinding, gear whine and scaring me 2 years ago to being quiet except in neutral idle (pilot bearing I think).